The .layer file has 2 sections. One is the layer definition (identical to MapGuide), the other is the feature source (also somewhat identical to MapGuide).
The feature source section describes the connection settings (in this case, to your SHP file). So all you have to do is just change the file/directory path to point to your new SHP file(s). This is assuming the new SHP is structurally identical to the existing SHP file.
Because if you have style rules on properties that don't exist in the new SHP file, there will be problems.
- Jackie